This sounds like her insecurity issues, pure and simple, to me. If I'm right, there is no real way round it, you either grin and bare it, or go.
It may be that she is the one needing a therapist rather than you.
BTW, I don't really understand the leg-crossing issue - everyone crosses their legs, male and female - so it sounds as though she is looking for things to make her seem 'threatened' in her mind, to reinforce her own belief that she isn't good enough as a woman... I've experienced that problem as well, I'm afraid.